The decision by Judge Yahia Dakrouri of the Administrative Court was expected after the high court's ruling last week. The country's election committee later will set a new date for the vote.

The Supreme Constitutional Court's ruling declared the law defining voting districts unconstitutional. The government is working on amending the law. The Supreme Election Committee said in a statement earlier that it is setting up a new timetable for elections whenever the law is ready. It was not clear how long it will take for the amendments to be written, but voting for a new parliament is expected to be delayed for at least several weeks.

The parliamentary vote initially was set to take place in phases beginning on March 22. It is the final phase in a transition period following the 2013 ouster of Islamist President Mohammed Morsi by the military.

Egypt has not had an elected legislature since 2012, when the Supreme Constitutional Court ruled that parliament's lower chamber was not constitutionally elected. Islamist supporters of Morsi - who was the president at the time - besieged the court ahead of a hearing in which a similar ruling against the upper chamber was expected.

The first two steps of the transition following Morsi's ouster were the adoption of a new constitution by referendum in 2014 and a presidential election, which former army chief Abdel-Fattah el-Sissi handily won.

Morsi's Muslim Brotherhood swept the first free parliamentary elections after the 2011 uprising that toppled longtime autocrat Hosni Mubarak. The group is now officially considered a terrorist organization, and thousands of its members, including most of its top leaders, are imprisoned.